Only, they weren't the first.
According to Run For Cover, a limited edition hardcover of the Principia Discordia was published by the Revisionist Press imprint of Gordon Press in 1976. I've no idea how large the print-run was, but their edition, ISBN 068575085X, apparently retailed for US$250 (link might be down: here's the Google cache). US$250!!!
Gordon Press were rumoured to have been a CIA front. Now, they're out of business. I guess their turnover wasn't sustainable.
Anyway, Run For Cover have bought their inventory. It includes copies of the hardcover Principia Discordia.
Well, I have the thing in my hands. It's 9"x6", red cover, gold printing. I'll upload a scan when I get the chance. Much to my chagrin, it's the 4th Edition, so my quest for the Myth of Starbuck continues.
Now, it looks authentic. Smells authentic. But it might be a scam. There's no publisher's imprint on the book. But it seems genuine to me. (But is it worth US$250? I think not...)
ED: Someone posted on USENET two years ago about this...